Star wheel operating mechanism

ABSTRACT

Bi-acting verge drive means for driving a star wheel with the verge means comprising a pair of pivotally supported pawls engageable with the wheel and mechanical or electrical actuator means operatively connected to at least one of the pawls and spring means connected to the pawls whereby the pawls co-operate to rotate the wheel. The star wheel is shown adapted to actuate a counter and means is provided for resetting of the counter.

[22] Filed:

United States Patent Soden 1 1 STAR WHEEL OPERATING MECHANISM [72] Inventor: George B. Soden, 108 Hickory Lane, Wolcott, Conn. 06718 Aprill9,1968 [21] Appl. N0.: 722,747

[52] [1.8. CI ..235/91 M, 235/92 C, 235/117 R [51] Int. Cl. ..G04b 39/00, G04b 15/00 [58] Field ofSearch ..235/117,9l.1,92 C, 92 H,

-151 3,700,163 1 Oct. 24, 1972 11/1963 Hartkorn ..235/92 3,112,068 3,141,611 7/1964 Ambrozaitis ..235/91 3,470,361 9/1969 Wollar ..235/92 Primary Examiner-Richard B. Wilkinson Assistant Examiner-Stanley A. Wal Attorney-March, Gillette & Wyatt [57] ABSTRACT Bi-acting vergedrive means for driving a star wheel with the verge means comprising a pair of pivotally supported pawls engageable with the wheel and mechanical or electrical actuator means operatively connected to at least one of the pawls and spring means connected tothe pawls whereby the pawls cooperate to rotate the wheel.

The star wheel is shown adapted to actuate a counter and means is provided for resetting of the counter.

20 Claims,'4 Drawing Figures PKTENTE D 241972 3.700.163

sum 2 [1r 2 INVENTOR- fcqse 5. Shaw 1 STAR WHEEL OPERATING MECHANISM This invention relates to star wheel operating mechanisms and more particularly to means for driving a star wheel and, also, means for resetting and indicator which is operatively connected to the star wheel.

In indicator devices, particularly multi-numeral drum indicators actuated by a star wheel driven by a pawl, it is desirable to be able to reset the indicator to a particular number easily. One way in which this has been done heretofore has been to move the verge into a neutral position in which it does not engage the star wheel and then rotate the star wheel, either directly or by means of a gear train.

In the present invention, the verge is divided into two pawls which are connected by a spring so that they move as a unit unless the spring force is overcome. With this arrangement, one of the pawls will normally be held out of engagement with the star wheel and, to reset the indicator, the other pawl may be pressed out of engagement with the star wheel by applying pressure to overcome the spring force. Simultaneously, a gear drive may be engaged to rotate the indicator wheel or wheels.

By virtue of the resilient connection between the pawls, at least one may be maintained in sufficient engagement with the star wheel at all times to assure that the wheel moves only one step at a time. The resilient connection also smoothes the operation of the device.

A principal object of this invention is to provide new and improved bi-acting verge means for driving and resetting a star wheel.

Another object is to provide a drive means for a star wheel which is adapted to actuate a decade or digital type indicator or counter, which can be of the mechanically or electro-mechanicallyactuated type.

' Other objects and advantages of the invention will be apparent from the following description taken in connection with the accompanying drawings. It will be understood thatchanges may be made in the details of construction and arrangement of parts shown and described without departing from the spirit of the invention as set forth in the appended claims, as the preferred form of the invention has been given by way of illustration only.

For a better understanding of the invention, reference should be made to the following detailed description and to the accompanying drawings, in which:

Referring to the drawings:

FIG. 1 is a top or plan view of an impulse or electromechanical counter embodying the invention;

FIG. 2 is a front view, partially in section, of the device shown in FIG. 1;

' FIG. 3 is a sectional view taken on line 33 of FIG. 1, looking in the direction of the arrows; and

FIG. 4 is a fragmentary bottom view thereof.

The device shown in FIG. 1 embodying the invention, by way. of illustration, comprises an electromechanical digital type counter which includes a housing, or frame, having a pair of parallel spaced sides and 11 connected at their front and rear ends by front and rear walls 12 and 13, respectively. A shaft 14 extends between the side plates 11 and 12 and on this shaft are mounted the three counter wheels, or drums, l5, l6 and 17. These drums are of conventional type and are interconnected by a conventional Geneva-type transfer or gear mechanism, which is driven by a star wheel 18 affixed to the shaft 14.

The counter wheels 15-17 are usually calibrated and designed to have 10 index positions for decade counting, but for special uses and purposes they may be differently calibrated with corresponding changes in the transfer gears.

While the counter might be actuated or operated by suitable mechanical means, the form of the invention shown is an electro-mechanical actuator which, as may be seenin FIG. 3, includes a coil 19 having a magnetic core 20 and terminals 21 and 22 to be connected to a source of electrical current. An armature, or clapper, 23 is pivotally mounted on a shaft 24 and one end 25 of the armature 23 is connected to an end of an armature spring 27 which has its opposite end connected to a rod 28 that extends between the sides 10 and 11.

Betweenthe shaft 14 and the shaft 24 is positioned another shaft 29 supported by the walls 10 and 11. An upperpawl 30 and a lower pawl 31 have hubs 32 and 33, respectively, pivotally mounted on the shaft 29, as shown particularly inFIG. 1. The pawls 30 and 31 are pivotally mounted in opposed, scissor-like relation and are resiliently connected together by a pawl spring 36, one end of which is connected to a stud 34 on the pawl 30 and the other end of which is connected to a stud 35 on the pawl 31. The pawls 30 and 31 are each provided with pointed portions 37 and 38, respectively, that engage star wheel 18 from nearly diametrically opposite sides. The pawls also have rounded projections 39 and 40, respectively, at the ends opposite the pointed por tions 37 and 38, and a lever arm 41 attached to the armature 23 extends away from the armature and between the juxtaposed rounded projections 39 and 40. This provides a rolling engagement between the ends of the pawls and the lever arm. in addition, as shown, the pawl 30 has a longer effective length (between the shaft 29 and the pointed portion 37) than the distance between the shafts 14 and 29, while the effective length of pawl 31 is less than the distance between these shafts. Each of the teeth of the starwheel 18 is symmetrical about a radial line through its tip and as a result of this fact and the relative effective lengths of the pawls, the starwheel 18 is caused to rotate in one direction as its teeth are alternately engaged by the pointed portions 37 and 38. This actuation of the starwheel 18 is similar to the actuation in US. Pat. No. 3,141 ,61 1.

It will be seen that the spring 27 resiliently biases the lever arm 41 against the end of one of the pawls and that the pawl arms are spaced apart by a distance slightly greater than the thickness of the lever arm 41 so that the pointed end 37 is clear of the star wheel 18 when the pointed end 38 fully engages the star wheel. The spring 36 urges the other pawl 31 normally into engagement with the star wheel, but permits a variable spacing between the pointed ends 37 and 38, which facilitates the action of the armature 23 and the lever arm 41 on the pawls 30 and 31 to rotate the star wheel 18, thereby effecting actuation of the counter.

The pawl 31 remains in fully-locked engagement with the star wheel 18, as shown in FIG. 3, during the first part of the motion of the armature 23 while the lever arm 41 moves toward the rounded portion 40. The other pawl 30 follows the lever arm during this motion as the rounded portion 39 remains in contact due to the force of the spring 36. As the lever arm strikes the rounded portion 40 and begins to exert pressure on it, the pawl 31 also begins to move. Continued movement of the armature 23 and the lever arm 41 eventually forces the pointed end 38 of the lower pawl 31 to disengage from the star wheel, or ratchet wheel, 18, but by this time, the pointed end 37 of the upper pawl 30 will have been interposed between two teeth on the opposite side of the star wheel to index the star wheel one step forward, or more precisely half a step forward, as the pointed end 37 moves into full engagement and the pointed end 38 is fully removed beyond the circular path of the tips of the teeth of the star wheel. The pivotal relationship between the pawls 30 and 31 permits at least one of the pointed ends 37 or 38 to be interposed between two teeth of the star wheel 18 at all times, thereby preventing any missed steps or double steps from occurringQThe star wheel movesone and only one full step forward for each complete back-andforth movement of the armature 23. In addition, the

resilient coupling between the pawls and 31 permits smoother operation of the star wheel and increases the life of the mechanism.

The resetting apparatus is shown in FIG. 4 and includes a setting socket 42 and a miter gear 43 on a shaft 44. A spring 46 presses the shaft 44 normally outwardly and must be overcome to move the gear 43 into mesh with a second miter gear 45. The shaft 44 has a yoke 47 on which a pin 48 is mounted inline with a spur 49 on the pawl 31, as shown in FIG. 3. The bevel, or miter, gear 45 carries a pinion 50 which, as shown in FIG. 1, meshes with a gear 51 on to a transverse shaft 52 journalled in the opposed plates 10 and 11. At its opposite end, the shaft 52 has affixed thereto a gear 53 which meshes with a gear 54 which in turn meshes with a gear 55 affixed to the star wheel 18.

Thus, assuming the lower order drum 17 to be free to rotate, it may be set to any desired position, and the other drums 15 and 16 along with it, through cascade operation, by pushing inwardly on the control socket 42. This pressure is transmitted via the yoke 47 and the pin 48 to the spur 49, and provided sufficient pressure is applied to overcome the force of the spring 36, disengages the pawl 31 from the star wheel 18. The force of the spring 27 as applied to the other pawl 30 must be sufficiently greater than the force of the spring 36 to keep the pawl 30 from following the pawl 31 during resetting. Continued inward movement of the shaft 44 causes engagement of the gears 43 and 45, and rotation of the control knob 42 then resets the drums 15-17 via the gear mechanism 50-55. When the control knob 42 is released, the spring 46 returns it and gear 43 to its forward, or non-engaging, position.

As will be seen from the above, the driving star wheel or cam 18 and impulse lever and pawl arrangement constitutes a positive drive for the counter drums and prevents independent advancement thereof since either pawl engaging the star wheel follows the lever arm 41 and either pawl disengaging from the star wheel is pushed by the lever arm 41. This provides positive drive of the star wheel 18 and, at the same time, substantially eliminates the possibility of lock-up through failure of either pawl to disengage.

What is claimed is:

1. Bi-acting verge means for driving a star wheel having symmetrical teeth and being rotatable about a first axis, said verge means comprising: first and second pawls of unequal effective length engageable with said wheel; pivotal means supporting said pawls to pivot about a second axis, said pawls being constrained to pivotal motion, said first pawl having a first end engageable with said teeth and located a radial distance from said second axis greater than the distance between said axes, and said second pawl having a first end engageable with said teeth and located a radial distance from said second axis less than the distance between said axes; actuator means engageable with at least one of said pawls; and spring means connected to said pawls whereby said pawls cooperate to rotate said wheel.

2. The bi-acting verge means of claim 1 in which said spring means is connected directly to said pawls.

3. The bi-acting verge means of claim 2 in which at least said first pawl comprises an arm on the other side of said pivotal means from said first pawl, and said spring means is connected to said arm.

4. The bi-acting verge means of claim 3 in which each of said pawls has an arm extending beyond the respective pivotal means supporting said pawls, and said spring means is connected directly to both of said arms.

5. The bi-acting verge means of claim 1 in which said pivotal means comprises a common axle supporting both of said pawls.

6. The bi-acting verge means of claim 1 in which said pawls engage said wheel from substantially diametrically opposite sides.

7. The bi-acting verge means of claim 1 in which said actuator means comprises a pivotally mounted member extending between said pawls.

8. The bi-acting verge means of claim 7 in which said actuator comprises a spring resiliently biasing said member against one of said pawls.

9. The bi-acting verge means of claim 7 in which said actuator means comprises an electromagnet and said member is an armature therefor.

10. The bi-acting verge means of claim 9 in which said member comprises an armature portion to be attracted by said electromagnet and a lever attached to said armature portion and extending at an angle thereto.

11. The bi-acting verge means of claim 7 in which each of said pawls comprises an arm extending beyond the respective pivotal means supporting said pawls, and said member extends between said arms.

12. The bi-acting verge means of claim 11 in which said arms are spaced apart by a distance greater than the thickness of said member.

13. The bi-acting verge means of claim 11 in which said arms comprise juxtaposed rounded ends and said member engages said ends whereby there is a rolling engagement between said ends and said member.

14. An indicator comprising: a first wheel having indicia thereon; and means to move said wheel in a series of steps, said means comprising a star wheel having symmetrical teeth and being connected to said first wheel to rotate on a common first axis, first and second pawls of unequal effective length engageable with said star wheel, pivotal means supporting said pawls to pivot about a second axis, said pawls being constrained to pivotal motion, said first pawl having a first engageable with said teeth and located a radial distance from said second axis greater than the distance between said axes, and said second pawl having a first end engageable with said teeth and located a radial distance from said second axis less than the distance between said axes, actuator means engageable with at least one of said pawls, and spring means connected to said pawls whereby said pawls cooperate to rotate said star wheel.

15. The indicator of claim 14 comprising second spring means connected to said actuator means to bias said first pawl out of engagement with said star wheel, said first-named spring means urging said second pawl into engagement with said star wheel.

16. The indicator of claim 15 comprising resetting means engageable with said second pawl to overcome the force of said first-named spring means and disengage said second pawl from said star-wheel.

17. The indicatorof claim 16 in which said resetting means comprises a plunger and said second pawl has an abutment in the path of said plunger.

18. The indicator of claim 16 in which said second spring means is more rigid than said first-named spring means.

19. The indicator of claim 16 in which said actuator means engages said, first pawl and said second spring means is connected to said actuator means to force the same against said first pawl to bias said first pawl out of engagement with said star wheel.

20. An indicator comprising: a first wheel to rotate in a series of steps; a star wheel having symmetrical teeth and being attached to said first wheel to rotate said first wheel on a first axis common to said first wheel and said star wheel; first and second pawls each centrally pivotally mounted to pivot about a second axis and each comprising a driving end to engage said star wheel and an arm at the other end, said driving ends being of different lengths and said first pawl having a first end against arm of said first pawl to rotate said armature and said pawls to a normal position in which said first pawl is out of engagement with said star wheel and outside of the path of the tips of said star wheel, whereby said first spring urges said second pawl into engagement with said star wheel, said arms of said pawls being spaced apart a distance in said normal position sufficient to permit said pawl to move to a position within the path of the tips of said star wheel before said second pawl is withdrawn from engagement with said star wheel. 

1. Bi-acting verge means for driving a star wheel having symmetrical teeth and being rotatable about a first axis, said verge means comprising: first and second pawls of unequal effective length engageable with said wheel; pivotal means supporting said pawls to pivot about a second axis, said pawls being constrained to pivotal motion, said first pawl having a first end engageable with said teeth and located a radial distance from said second axis greater than the distance between said axes, and said second pawl having a first end engageable with said teeth and located a radial distance from said second axis less than the distance between said axes; actuator means engageable with at least one of said pawls; and spring means connected to said pawls whereby said pawls cooperate to rotate said wheel.
 2. The bi-acting verge means of claim 1 in which said spring means is connected directly to said pawls.
 3. The bi-acting verge means of claim 2 in which at least said first pawl comprises an arm on the other side of said pivotal means from said first pawl, and said spring means is connected to said arm.
 4. The bi-acting verge means of claim 3 in which each of said pawls has an arm extending beyond the respective pivotal means supporting said pawls, and said spring means is connected directly to both of said arms.
 5. The bi-acting verge means of claim 1 in which said pivotal means comprises a common axle supporting both of said pawls.
 6. The bi-acting verge means of claim 1 in which said pawls engage said wheel from substantially diametrically opposite sides.
 7. The bi-acting verge means of claim 1 in which said actuator means comprises a pivotally mounted member extending between said pawls.
 8. The bi-acting verge means of claim 7 in which said actuator comprises a spring resiliently biasing said member against one of said pawls.
 9. The bi-acting verge means of claim 7 in which said actuator means comprises an electromagnet and said member is an armature therefor.
 10. The bi-acting verge means of claim 9 in which said member comprises an armature portion to be attracted by said electromagnet and a lever attached to said armature portion and extending at an angle thereto.
 11. The bi-acting verge means of claim 7 in which each of said pawls comprises an arm extending beyond the respective pivotal means supporting said pawls, and said member extends between said arms.
 12. The bi-acting verge means of claim 11 in which said arms are spaced apart by a distance greater than the thickness of said member.
 13. The bi-acting verge means of claim 11 in which said arms comprise juxtaposed rounded ends and said member engages said ends whereby there is a rolling engagement between said ends and said member.
 14. An indicator comprising: a first wheel having indicia thereon; and means to move said wheel in a series of steps, said means comprising a star wheel having symmetrical teeth and being connected to said first wheel to rotate on a common first axis, first and second pawls of unequal effective length engageable with said star wheel, pivotal means supporting said pawls to pivot about a second axis, said pawls being constrained to pivotal motion, said first pawl having a first engageable with said teeth and located a radial distance from said second axis greater than the distance between said axes, and said second pawl having a first end engageable with said teeth and located a radial distance from said second axis less than the distance between said axes, actuator means engageable with at least one of said pawls, and spring means connected to said pawls whereby said pawls cooperate to rotate said star wheel.
 15. The indicator of claim 14 comprising second spring means connected to said actuator means to bias said first pawl out of engagement with said star wheel, said first-named spring means urging said second pawl into engagement with said star wheel.
 16. The indicator of claim 15 comprising resetting means engageable with said second pawl to overcome the force of said first-named spring means and disengage said second pawl from said star-wheel.
 17. The indicator of claim 16 in which said resetting means comprises a plunger and said second pawl has an abutment in the path of said plunger.
 18. The indicator of claim 16 in which said second spring means is more rigid than said first-named spring means.
 19. The indicator of claim 16 in which said actuator means engages said first pawl and said second spring means is connected to said actuator means to force the same against said first pawl to bias said first pawl out of engagement with said star wheel.
 20. An indicator comprising: a first wheel to rotate in a series of steps; a star wheel having symmetrical teeth and being attached to said first wheel to rotate said first wheel on a first axis commoN to said first wheel and said star wheel; first and second pawls each centrally pivotally mounted to pivot about a second axis and each comprising a driving end to engage said star wheel and an arm at the other end, said driving ends being of different lengths and said first pawl having a first end engageable with said teeth and located a radial distance from said second axis greater than the distance between said axes, and said second pawl having a first end engageable with said teeth and located a radial distance from said second axis less than the distance between said axes; a first spring resiliently urging said arms together; an electromagnet; an armature pivotally mounted adjacent said electromagnet to be attracted thereby; an actuator connected to said armature and extending between said arms; pivotal mounting means for said actuator; and second spring means connected to said actuator and resiliently biasing said actuator against arm of said first pawl to rotate said armature and said pawls to a normal position in which said first pawl is out of engagement with said star wheel and outside of the path of the tips of said star wheel, whereby said first spring urges said second pawl into engagement with said star wheel, said arms of said pawls being spaced apart a distance in said normal position sufficient to permit said pawl to move to a position within the path of the tips of said star wheel before said second pawl is withdrawn from engagement with said star wheel. 